


Demoralized Oath

by TheNightWatcher



Category: New Dangan Ronpa V3: Everyone's New Semester of Killing
Genre: Alternate Universe, Alternate Universe - Fantasy, Animal Death, Big Brothers, Branding, Brotherly Affection, Brutal Murder, Descent into Madness, Fanfiction of Fanfiction, Fluff and Angst, Gift Work, Implied/Referenced Incest, Little Brothers, Minor Character Death, One Shot, Psychological Horror, Some magic
Language: English
Status: Completed
Published: 2020-05-15
Updated: 2020-05-15
Packaged: 2021-03-03 00:28:38
Rating: Teen And Up Audiences
Warnings: Rape/Non-Con, Underage
Chapters: 1
Words: 3,999
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24195940
Author URL: https://archiveofourown.org/users/TheNightWatcher/pseuds/TheNightWatcher
Summary: The Child of Lust wasn't always as deranged as most know him. He once had a family. He once had a brother. An older sibling who wanted to help him, but simply didn't know how.Tamekichi falls into madness. His magic is too unstable and so are the responsibilities thrust onto him. He drags the rest of his family into his tantrum.(And Koki-Nii will love him nevermore.)What a fitting result, for a Child of Chaos.
Relationships: Oma Kokichi & Tamekichi Oma
Comments: 4
Kudos: 9





	Demoralized Oath

**Author's Note:**

  * For [MinawaKitten](https://archiveofourown.org/users/MinawaKitten/gifts).
  * Inspired by [Flowering Recovery: Suzuran](https://archiveofourown.org/works/13091466) by [MinawaKitten](https://archiveofourown.org/users/MinawaKitten/pseuds/MinawaKitten). 



Kokicki Ouma had been sleeping on his mother's lap during a cold, rainy day on a Sunday night. The living room had a simple fireplace, and the rug was perfect to sit on. His mother always tells him a story during thunderstorms to calm him down from the roar of the weather. Stories about magic and adventures. He would grow sleepy after all the excitement, then rest. She was warm, a pillow barrier to his nightmares. Her fingers gently brushed his hair while he snuggled and occasionally snored while the rain hit the windows.

The door slams open, the storm from the outside howling into the living room.

Kokichi wakes with a jolt, rubbing at his eyes as he registers running steps. "Papa?" He murmurs, sleepy, and wondering.

His mother stands, scooping him into her arms as she looks to meet the man who entered with haste. There's a blur of words as Kokichi is gently put on the couch and his mother rushes over with pale light between her fingers. The little boy immediately became aware, blinking as he realized there was a third person between his parents.

A boy, younger than him by a couple of years or so. He was bloody, a head wound dripping red, and eyes glued shut. The other boy didn't seem to be breathing. There wasn't a hint of life, not unlike his parents who speak in a hurried tongue, or their quick breaths. Only complete and utter stillness.

Kokichi stares. He stares at the red, unable to look away from the liquid beginning to pool. The very scarlet drips between his Papa's fingers, staining his mother's clothes.

Kokichi bursts into tears. He doesn't know what's happening. There's too much red-

"Kokichi!" His mother snaps, commanding, stern. He quiets, blinking owlishly. "It's alright. He's fine. Just don't look, okay sweetie? Okay?"

The storm continues to roar but thankfully, his father closes the open door.

The little boy nods, rubbing at his eyes and finally looking away.

* * *

"Tamekichi! Tamekichi!" Kokichi chirps, stomping around the house with a toy dinosaur in hand. "Rawr! Ima get you if you're bad at hiding!" He throws himself into the halls and down the stairs. He hops into the living room, checking the couches and taking a look under the cushions. "Rawr, where are you, snack?!"

"Noo!" His little brother whines and Kokichi perks up at the nearby sound.

"Come here! I, the black dragon, am going to gobble you up! Rawr!" His purple hair bounces as Kokichi tackles an empty blanket. Building blocks collided with his side as the decoy dug into his ribs. He squeaks, rubbing at the aching skin. "Wow, you play dirty, don't ya?" Kokichi huffs, catching sight of his target huddling further into the shadows of the empty fireplace.

 _Got you,_ Kokichi cackles to himself, sneaking up behind the other boy before attacking him with a vicious assault of tickling. The dinosaur drops onto the floor as Kokichi makes sure the target has no way of retreat.

Tamekichi bursts into both laughter and a squeal. Kokichi doesn't let up until his brother pushes at his chest.

"I give, I give! Koki-Nii, _no!"_

Kokichi laughs, releasing him, and Tamekichi pouts before tackling him to the ground. Kokichi squeaks, and Tamekichi giggles, the two wrestling on the floor as they declare who won a sound battle between a dragon and a dragon slayer. They create 'dragon sounds' and faked growls as they roll.

"Kokichi! Tamekichi! Dinner, time!" Their mother calls, and both boys pause in their play-fighting.

"Oh," Kokichi mutters, getting to his feet while his brother does the same. "Race you?"

"Yeah!" Tamekichi beams, rushing off.

"Gah! You cheater!" Kokichi runs and stumbles. He falls backward on the fallen dinosaur. "Ouch!"

Kokichi sits up, rubbing the back of his head as he peers over at the empty fireplace.

...At least it _should_ be empty.

Rats. Dead rats, ripped open, and limbs missing. The blood was not too dry but not completely fresh either. Kokichi jumps away, fingers trembling as he observes the deceased animals inside the fireplace. Had his brother been hiding in _there?_ Tamekichi could've gotten hurt! What could've torn up the rats? Did a cat sneak in here? Was Tamekichi unaware of this when he was hiding there?

"Kokichi!" His mother calls, and Kokichi flinches.

"C-Coming!"

In a haste, Kokichi grabs the blanket. He collects the dead animals with a whimper, rolling the sheet up, and opening the living room window. The trash can is just out of reach, so Kokichi tosses it with all of his strength. The bundle strikes true, and he exhales in relief before scurrying off to the kitchen.

"Okasan, I gotta wash my hands first!"

Kokichi decides not to say anything when he notices patches of red under Tamekichi's fingertips as his little brother eats spaghetti. Kokichi tells himself it's the sauce and stabs a fork into a meatball. It's soft and chunky, just like the rats.

Kokichi decides he's no longer hungry.

* * *

Later that night, when Tamekichi crawls into their shared bed, Kokichi decides to speak up.

"Did you see anything weird in the fireplace?"

His little brother blinks back in the dark, mouth twisting. "No? Was there something there?"

"Forget it," Kokichi mumbles.

It must've been the sauce. The red _must've_ been. He reinforces the thought as his little sibling curls into his back and blissfully falls asleep. Tamekichi snores, light and carefree. Kokichi pulls the blanket over them.

"...Night."

He thinks of chasing his little brother up and down the house in tag, playing pretend, and sometimes getting into minor fights. The two would always make up, and their parents would coo about how adorable they are. His mother once said, older children have to protect their younger siblings.

Kokichi vows to fight the monsters in the dark for his precious little brother.

* * *

The incident has been shoved to the back of his mind as seasons pass and years fly by.

One day, Kokichi peers into their shared bedroom to find Tamekichi curled up in a blanket. He's staring at the corner of the wall. The room is dreadfully quiet, the sound of breathing absent. There's a wisp of _something,_ but Kokichi can't put his finger on it. Tamekichi doesn't react to his presence.

"Tame-chan?" Kokichi quietly calls, ignoring a newly formed pit in his stomach.

His brother doesn't respond.

Kokichi gently pushes the door open. His younger sibling mumbles incoherency, pulling the blanket over his head. "Tamekichi, are you okay?" He tries because Tamekichi isn't usually _this_ quiet.

"No." His little brother replies, and Kokichi takes a seat beside him with crossed legs.

"Do you want to talk about it?" Kokichi tries. "I can get Okasan? Papa?" He offers because sometimes talking to her works. He shifts, prepared to either stay or leave the room for one of the current adults in the house.

"No," Tamekichi repeats. "Just," Tamekichi's voice is muffled from the blanket. "Just leave me alone…" His voice is raspy. Was he sick?

"I won't," Kokichi tells him, crossing his arms. "I'm not going to. You don't sound too good." Kokichi bows his head.

"I _don't_ feel good." Tamekichi murmurs. "They won't shut up. Do you hear them too?"

Kokichi pauses. "You mean when Okasan and Papa argue sometimes at night?"

Tamekichi doesn't reply for a very long time. Kokichi ignores the sweat on his back. It's gross, but he refuses to retreat when his little brother needs him.

"...Mhm," Tamekichi finally replies, voice hesitant, and Kokichi couldn't help but wonder why.

He engulfs Tamekichi in an embrace anyways, holding him tightly. "It's okay! I mean, adults argue lots, so I'm sure it's fine. I'm still here, so if anything happens I'll be the one to protect you." Kokichi peers at the covered bundle, noticing how his little sibling stuttered in breaths. "Okay? I promise!" This is how it should be, shouldn't it?

"You won't ever leave me?" Tamekichi sniffles.

Kokichi huffs. "What? Do you doubt me?" He pokes at the bundle's stomach, grinning when Tamekichi giggles. "Your best older brother?"

"Koki-Nii!" Tamekichi whines as Kokichi begins to tickle him.

"Nah! I won't forgive you, dummy!" Kokichi cackles because yes, this is more like it. Teasing Tamekichi into giggles and fights.

"You're the worst!"

"You know you love me! And I love you too so that's okay!" Kokichi laughs, yelping when the bundle throws itself at him without warning. He blinks as Tamekichi effortlessly trapped him with his legs and arms, hands beside Kokichi's head. Dark eyes close to purples, Kokichi blinks once, twice, before realizing he couldn't get up with this odd position.

"Er," Kokichi tries because now he's very confused by the lack of space. "Tamekichi? You're a little…" Too close, you're being strange. He doesn't want to upset his little brother though and patiently waits. Is he breathing too hard? "Are you okay?" Kokichi asks and frowns as the other boy releases a shrilly giggle. Like a sick cat.

"You love me?" His brother questions, quiet.

"Yeah?"

"Really?" Their noses are touching.

"Uh-huh?" Kokichi can't see anything in Tamekichi's eyes. This activates the tiny prickles of ice in his fingers. He doesn't know how to deal with this new look. His brother's normal hues of curiosity look wild and wide. As if Tamekichi was seeing something he couldn't. What does this…?

"Hey. Hey, Koki-Nii…"

Kokichi swallows the lump in his throat and dismisses the shiver in his spine. This...This should be okay, right? There's nothing wrong with this heavy atmosphere or the dangerous vibes. He shouldn't be afraid of Tamekichi. Tamekichi is, he's-

Kokichi squeaks when Tamekichi licks his ear like a _dog._ It's slimy, salvia cooling on wet skin as the pinned boy shivers. His little brother pulls back a little as if to observe Kokichi's reaction.

"Do you know what people do when they _love_ one another? Do you, Koki-Nii?"

Tamekichi looks ecstatic. The depths in his eyes cannot be reached. Kokichi can't move and his eyes are beginning to sting.

"Kokichi! Did you clean up your toys?" Their mother calls from downstairs. He can hear the water running, their mother washing wishes, and blissfully unaware of what was happening above.

He took the outing. Reckless, he flails, Tamekichi falling off by a measure of luck.

"Sorry, GottaGoOkasan'sCalling!" The stairs were an object of escape.

Kokichi doesn't look back. He was too afraid to. In retaliation for his cowardly actions, Kokichi took a sponge from the sink and thoroughly scrubbed at his ear when his mother left to fetch a broom. He couldn't hear his little brother after passing by the staircase and asks his mother about him.

"What about Tamekichi? He's taking a nap." She gently told him, and Kokichi wonders if that was what he was doing. "You're a good Nii-san, Kokichi. I'm happy for the two of you." She pats his head and continues to sweep. Kokichi peers back at the stairs, but he's too terrified to climb. His heart won't calm down and either will his trembling fingers.

Regardless of his decisions, Tamekichi doesn't talk with him for the rest of the day.

* * *

Papa isn't home, and their mother stepped out for a moment. Kokichi thought it would be fitting to get Tamekichi some fruit since his little brother was just a growing boy! He scrambled into the kitchen, swiping a couple of apples before running up to their room. The area is oddly quiet but he preferred it to Tamekichi occasionally whispering to himself. Honestly, that boy...Kokichi is a little worried.

Tamekichi has been acting a _little_ strange lately. He's been staying in their room more often. At first, Kokichi would attempt to coax him out but after he's been hit with a thrown building block out of annoyance, Kokichi decided to tell their mother.

She told him everyone needs their alone time, and while Kokichi agrees, he doesn't think this is normal. ...But what does he know? Kokichi isn't grown-up yet. He kicks the door open with all the dramatic bits he could gather within his soul. "Tamekichi!" Kokichi ballows as he enters the room. "I have brought us food!" Fresh, from the kitchen bowl!

He pauses.

Tamekichi freezes. His fingers are dripping red, and there's a bluebird under his hand. The winged creature had already stopped moving, the smell itching Kokichi's senses as Tamekichi scrambled to cover the bird up with a blanket. "Koki-Nii!" He squeaks, the compliant ringing against his ears. "I'm sorry! I was just, um," He tries to smile, and Kokichi blinks as his little brother's expression becomes dazed and steel-like.

"...Please don't tell Okasan."

Kokichi thinks of the rats. He thinks of the other messes he's found but thought nothing of it. An invisible cat was outrageous. It had always been his little brother messing with little lives. Kokichi swallows, itching the back of his neck. "Er," He coughs, backing out of the room in a swift retreat. "Right, I'ma just head out then. Nothing to see here…"

"Don't tell Okasan!" Tamekichi screams, and Kokichi is roughly pushed.

Kokichi blinks as the ground leaves him. Tamekichi also blinks.

They're on the second floor. Their bedroom is by the staircase.

As Kokichi falls down the stairs and shrieks when he hears a _crack_ creak out of his leg, Tamekichi whispers apologies before it all goes dark.

When Kokichi wakes again, he's at the hospital. Tamekichi doesn't make eye-contact with him while their parents peer over his hospital bed with dripping concern. A concussion and a broken leg, the doctors said.

"Kokichi…We're sorry." His mother begins. She looks regretful. It looks all _wrong_ on her face when it wasn't her fault. "We'll be sure to make the stairs a lot safer for you."

...Maybe. Maybe Tamekichi didn't mean to hurt him. He'll think that's the case. There's no way his little brother would hurt him for no reason, right? Maybe, maybe he deserved it. After all, Kokichi since his actions would've hurt his brother, perhaps this was retribution? His brother wouldn't hurt him intentionally after all!

* * *

Kokichi can't move as his father is cut down like ribbons. Red floats out of his Papa's neck like a doll's stuffing. The room is in chaos but there's not a scream or a shout. He's stiff and shaking, as his mother stands between him and Tamekichi's rampaging form. His little brother looked like a literal monster with the Cheshire-cat smile and raging claws for arms.

The transparent armor was just like their mother's little tricks, but much more bold and profound.

His mother is saying something, calm and soothing.

Tamekichi stiffens, dark eyes shining as his mouth trembles. "Y-You think this is a joke? Just give it to me already!" He shrieks, hectic, a storm, and unstable thunder all at the same time. "Your _magic,_ your _life!"_ Tamekichi hisses. "I love you, so can't you just _stop trying to convince me not to do this? I don't care!_ I can't care! None of this matters but I'll make sure it doesn't hurt, Okasan! _"_

Kokichi chokes on his words. There's too much red. He tastes bile. Kokichi hides into his mother's side but he doesn't look away from his little brother. His adorable, weird baby brother who would throw building-blocks at him. The same sibling who would giggle along with him when they ambushed their Papa when he came home.

"T-Tame-Tameki," Kokichi rasps. His mother gently squeezes his hand, her eyes shining brighter than he's ever seen.

"Shut _up!_ Koki-Nii!" Tamekichi screams, stabbing forth in a blur.

Their mother is cut down as she tenderly shoves her elder son a few steps away. She hadn't protected herself. Kokichi knew why. She would _never_ hurt them, her 'precious boys', and he shrieks from the realization as Tamekichi rips into her. The younger boy does not hesitate. He shreds and stabs, hissing, snarling like an animal as red, red _red,_ spills into the air in puffy clouds.

It makes no sense. Nothing about this made sense. Blood should not be stuffing. He's scraped his knees before, saw it run like water. Why was it _stuffing?_ His mind is swimming. Kokichi can't breathe. He knew his mother was dying. He knew his Papa was dead. Nothing is correct.

But...Why? Why was Tamekichi doing this to them? Weren't they family?

Kokichi jolts as he focuses on his mother's limp arm, looks at his Papa's unmoving fingers and grips his own arms in fright.

" _Stop it!"_ Kokichi screeches, hysterical. "Stop it, _stop!_ Tamekichi!" Why was he _still_ stabbing at someone who wasn't responding? "Tamekichi, just _stop!"_ His surroundings kept blurring and everything was shaking under the horrible sounds of ripped stuffing colors of red. "Okasan's dead! She's already _gone!_ " He shrieks. "Just stop it already! Leave Okasan alone!" Everything hurts. His head hurts, his stomach hurts, it's all wrong.

And Kokichi knows this isn't a dream.

He can't even cry as Tamekichi twitches into unrest, jerking upwards like a badly controlled puppet. He sniffles as his little brother steps off their mother's mauled body as if it were a ripped-up stuffed animal. Tamekichi walks forward with a purpose and shaky claws, Kokichi feels the utter _loathe_ burning in his belly but cannot acknowledge it.

He cries out, as Tamekichi pounces and grabs his throat. Kokichi begins to choke and sputter, knowing he was the last remaining family member to die. Kokichi tries to scream and scratch, but the lack of oxygen is itching at his senses.

Regardless, he tries to say Tamekichi's name one last time. His eyes are locked on empty dark hues, remorse nonexistent.

Just as everything was going dark, a rough landing assaulted his senses. Kokichi spits and hacks, eagerly grasping oxygen before he's roughly pinned against the floor. He wheezes and struggles limply. Tamekichi is far too strong to escape, and he whimpers.

"Hey. Koki-Nii...Do you still love me?" His little brother whispers and Kokichi is reminded of the months ago with a curled up blanket and a disturbing scene. "Even though I made a mess. Even though I ruined everything." Tamekichi mumbles.

Kokichi coughs and wheezes, dark violets glancing over to their deceased parents. He tears up but does not look away. Kokichi knew this would be damning himself but neither option was a _win._ Kokichi covers his eyes and jerks his head up and down with a whimper. He can't _look_ at his younger brother. The monster. The creature who tore their family apart in ten minutes.

"That's good! That's...So, so good. I was worried, you know? I don't actually want to kill you...Koki-Nii…" Tamekichi's voice was horribly quiet. Almost like a mouse, a threading piece of ice slowly melting in patience. "Koki-Nii was so kind to me! Gave me piggy-back rides, petted my head," He giggles. "Kissed my forehead. Saved me from nightmares! Told me he _loved me!_ "

"Okasan did those things too." Kokichi rasps, trembling when the air becomes lethal. "Papa did those too. Why am I special?"

Tamekichi shifts. "They aren't the same as you, Koki-Nii…"

" _Why?_ " Kokichi hisses despite his shattered heart and ever-growing fear.

"Because...We were meant to be together!" Tamekichi protests, as if this were normal. And their parents weren't dead because of this selfish wish. "Together forever! Partners," Tamekichi shudders. "But they told me Okasan would never allow it. She would neverrr," Tamekichi trails off, dazed. "Shhhe would never allow you to come with us. That's okay, though. She's dead now. And Papa too. They can't do anything. Not when they're dead. I've seen dead things. Hey, have you?"

Kokichi has _no_ idea what Tamekichi is talking about. He tries to reason with him anyway, despite his pounding heart. "Tamekichi...Tamekichi, I can't...Not when you," Kokichi's throat closes up. He didn't mean to say what was on his mind and it had slipped out.

Tamekichi blinks very slowly as if comprehending those words. "Was it a lie when you said you wouldn't leave me?"

Kokichi can't speak. His little brother's fingers have him pinned just like the night all those days ago. This time it wasn't the grip around his nape, but the fear from _before._ Nothing was stopping Tamekichi, but stopping him from _what?_ Kokichi didn't know. He didn't know and it was scary. He wanted to cry, and his vision kept stinging with blurred tears.

Kokichi jerks his head forward. A successful head-butt, with Tamekichi squeaking and Kokichi bolting out of the bloody room with reckless abandon.

"Koki-Nii!" Tamekichi whines in the distance and Kokichi bites his lip. "Koki-Nii don't leave me! I don't want to chase you!" The following steps fill him with horrible jagged glass. Kokichi hides in the kitchen cupboard. For a moment, all is quiet. Did his little brother go upstairs to check the bed?

He's pulled out by the hair. Kokichi spits and yells. He doesn't want to die. He doesn't want to do whatever Tamekichi _wants._ Kokichi knows it's bad. His _little brother_ is bad! What is supposed to do? His scalp feels like it's on fire!

"No! No! Let me go!" Kokichi cries, lips trembling. "Tamekichi, no!" He continues to struggle and scream despite being pulled up the stairs. His little brother is unresponsive to these pleas.

"It's only going to hurt for a little, Koki-Nii." Tamekichi calmly says, and Kokichi freezes. "Don't worry. You won't die. I still need you." They make it to their shared bedroom. Kokichi scrambles to escape but is easily thrown inside. Tamekichi locks the door as if there were anyone left in the house to knock before he smiles, dark eyes sprinkled with content.

"What are you going to do?" Kokichi shivers, "I don't have anything...I don't want anything."

Tamekichi raises a hand, a sharp metal ceasing Kokichi's heart activity for a solid second. "I just need to draw something. Stay still, okay? Then I'll reward you." Those words. Those words are _something_ dangerous.

Kokichi throws himself against the wall. His chest is heaving as his brother takes a step forward "No. Stay away. I don't want that near me," Kokichi's eyes darted around the room. There was nothing he could use to defend himself. He shivers and sniffles, blinking fast. "Please. _Please._ Tamekichi, don't do this…" Begging. Kokichi was begging. He had to. Anything but this. No. No!

Tamekichi smiles, big and bright as the times he drew pictures with a sharp crayon.

"I'll be careful, Koki-Nii!"

Kokichi doesn't know if careful means Tamekichi running a scalpel down his skin with practiced guidance, and kissing his neck while he cries-But Kokichi screams himself hoarse anyways.

"I'll make sure you never leave my side, Koki-Nii…"

* * *

Perhaps it's because Kokichi doesn't talk to him with warmth in his words any longer...Tamekichi treats him much more violently throughout the years. Kokichi snaps back with equal spite and ends up with more injuries than he knows what to deal with. He's sick of it all. The sounds. The unwelcome touches. _Those horrible nights where his opinion means nothing._ His brother's uncontrollable personality and actions. Waking up to being strangled only for Tamekichi to release him at the last moment with a giggle and flick his nose like a solid mocking.

There have been countless escape attempts. All of them failed. Tamekichi would always, _always_ find him. Trap him, then proceed to punish him in the most violent and sometimes sickening ways.

Sometimes, Kokichi thinks it would've been better if he died alongside his parents.

Kokichi bitterly vows to _actually_ escape his current situation. Even for a few years.

* * *

He does just that, and Kokichi couldn't help but feel viciously satisfied for staying out of Tamekichi's sight proximity for just a little while.

He knows better. This damned mark will help Tamekichi find him but there are more pressing matters. Like this killing game. However, one thing was for certain.

Tamekichi never was, and never will be, his little brother.

**Author's Note:**

> So. I've been bingeing MinawaKitten's 'Flowering Recovery: Suzuran' fanfiction, and I got inspired by their take/creation on Ouma's backstory.
> 
> Also. If there's something I really enjoy, it's writing the story of a villain. Villains are just as important as the hero, so I simply HAD to write this. I realized half-way through there were differences (so I labeled it an AU of the fanfic) but I wanted to finish it regardless. I hope you enjoyed! ...The tags are only extreme because I don't want others to be too uncomfortable. Thanks for reading.
> 
> Lust: -DESIRE.-
> 
> [Desire for? For whom? For what reason?]
> 
> {What if Tamekichi realized as a being of chaos, he was bound to be alone? Despite the need for magic eating away at him, do you think he latched onto his brother as the only person who wouldn't abandon him? But this obsession grew and grew, and he didn't want to destroy his family despite what he hears behind closed doors, only to do so by his own hand anyway.}


End file.
